Does the osteoarthritic shoulder have altered rotator cuff vectors with increasing glenoid deformity? An in silico analysis.

Background: A transverse force couple (TFC) functional imbalance has been demonstrated in osteoarthritic shoulders by recent 3-dimensional (3D) muscle volumetric studies. Altered rotator cuff vectors may be an additional factor contributing to a muscle imbalance and the propagation of glenoid deformity.

Methods: Computed tomography images of 33 Walch type A and 60 Walch type B shoulders were evaluated.

What Is the Most Reliable Method of Measuring Glenoid Bone Loss in Anterior Glenohumeral Instability? A Cadaveric Study Comparing Different Measurement Techniques for Glenoid Bone Loss.

Background: Preoperative quantification of bone loss has a significant effect on surgical decision making and patient outcomes. Various measurement techniques for calculating glenoid bone loss have been proposed in the literature. To date, no studies have directly compared measurement techniques to determine which technique, if any, is the most reliable.

Does the Walch type B shoulder have a transverse force couple imbalance? A volumetric analysis of segmented rotator cuff muscles in osteoarthritic shoulders.

Background: The etiology of the Walch type B shoulder remains unclear. We hypothesized that a scapulohumeral muscle imbalance, due to a disturbed transverse force couple (TFC) between the anterior and posterior rotator cuff muscles, may have a role in the pathogenesis of the type B morphology. The purpose of this study was to determine whether there is a TFC imbalance in the Walch type B shoulder using an imaging-based 3-dimensional (3D) volumetric and fatty infiltration assessment of segmented rotator cuff muscles.

Does proximal porous coating in short-stem humeral arthroplasty reduce stress shielding?

Context: Short-stem humeral designs in shoulder arthroplasty have been introduced recently. A retrospective cohort study was conducted to determine if newer proximal porous titanium coating in humeral short stems produced clinical and radiologic improvements.

Method: Short-stem humeral implants (Tornier Ascend, Wright Medical) were used in 46 anatomical total shoulder replacements from October 2012 to December 2015.

Axillary Nerve Position in Humeral Avulsions of the Glenohumeral Ligament.

Background: The axillary nerve is at risk during repair of a humeral avulsion of the glenohumeral ligament (HAGL).

Purpose: To measure the distance between the axillary nerve and the free edge of a HAGL lesion on preoperative magnetic resonance imaging (MRI) and compare these findings to the actual intraoperative distance measured during open HAGL repair.

Study Design: Case series; Level of evidence, 4.

Design, Modeling, and Evaluation of the Eddy Current Sensor Deeply Implanted in the Human Body.

Joint replacement surgeries have enabled motion for millions of people suffering from arthritis or grave injuries. However, over 10% of these surgeries are revision surgeries. We have first analyzed the data from the worldwide orthopedic registers and concluded that the micromotion of orthopedic implants is the major reason for revisions.

Evidence of healing of partial-thickness rotator cuff tears following arthroscopic augmentation with a collagen implant: a 2-year MRI follow-up.

Background: partial-thickness rotator cuff tears frequently enlarge due to increased local strain and often progress to full-thickness tears. Studies suggest the addition of new tendinous tissue to injured cuff tendons would significantly decrease peak strain, possibly protecting against tear progression. The aim of this study was to assess the ability of a highly-porous collagen implant to induce new tissue formation and limit tear progression when placed on the bursal surface of partial-thickness cuff tears.

Preliminary investigation of a biological augmentation of rotator cuff repairs using a collagen implant: a 2-year MRI follow-up.

Background: the inability to restore the normal tendon footprint and limit strains on the repair site are thought to contribute to re-tearing following rotator cuff repair. The purpose of this study was to use a collagen implant to augment rotator cuff repairs through the restoration of the native tendon footprint and the induction of new tissue to decrease overall tendon strain.

Methods: repairs of full-thickness rotator cuff lesions in 9 adult patients were augmented with a novel collagen implant placed over the bursal surface of the repair.

The influence of intraoperative factors and postoperative rehabilitation compliance on the integrity of the rotator cuff after arthroscopic repair.

Background: The purpose of this study was to determine when cuff re-tear commonly occurs in the postoperative period and to investigate the clinical factors that might predispose to an early cuff re-tear.

Methods: All patients with rotator cuff (supraspinatus ± infraspinatus) tear that required arthroscopic repair during the period between June 1, 2010, and May 31, 2012, with completed serial ultrasound examinations at 6 weeks, 12 weeks, and 26 weeks postoperatively were included. Intraoperative findings were noted.

Cerebral oxygenation using near-infrared spectroscopy in the beach-chair position during shoulder arthroscopy under general anesthesia.

Purpose: To examine the risks of shoulder arthroscopy in the beach-chair position (BCP) as opposed to the lateral decubitus position. The challenge during general anesthesia, particularly with the patient in the BCP, has been to ascertain the lower limit of blood pressure autoregulation, correctly measure mean arterial pressure, and adequately adjust parameters to maintain cerebral perfusion. There is increasing concern about the BCP and its association with intraoperative cerebral desaturation events (CDEs).

The effect of humeral avulsion of the glenohumeral ligaments and humeral repair site on joint laxity: a biomechanical study.

Purpose: The aims of this cadaveric study were to assess the effect of different sizes of humeral avulsion of the glenohumeral ligament (HAGL) lesions on joint laxity and to investigate any difference between repairs with anchors placed in a juxtachondral position and repairs with anchors placed in the humeral neck.

Methods: Glenohumeral specimens were tested on a shoulder laxity testing system with translations applied anteriorly up to 30 N, with the joint in 60° of glenohumeral abduction. Testing was conducted in neutral rotation and under 1-Nm external rotation for 5 specimen states: intact, medium HAGL lesion (4:30 to 5:30 clock-face position), large HAGL lesion (3:30 to 6:30 clock-face position), repair with juxtachondral suture anchors, and repair with humeral neck suture anchors.

The effect on loop elongation and stress relaxation during longitudinal loading of FiberWire in shoulder arthroscopic knots.

Purpose: This study examined the viscoelastic properties of 6 common arthroscopic sliding knots (Tennessee slider, Roeder knot, SMC knot, Duncan loop, Weston knot, and Nicky's knot) with 3 reversing half-hitches on alternating posts, tied with No. 2 FiberWire (Arthrex, Naples, FL). Knot configuration was designed to simulate a double-row rotator cuff repair with suture bridges.

Rugby Union on-field position and its relationship to shoulder injury leading to anterior reconstruction for instability.

Due to the unique demands of each position on the Rugby Union field, the likelihood of an athlete sustaining a dislocation of their shoulder joint that requires surgical reconstruction may be affected by their position on the field. 166 patients with 184 involved shoulders requiring anterior reconstruction following an on-field Rugby Union injury between January 1996 and September 2008 were analysed. The mean age at time of injury was 18 years with the mean age at time of surgery being 20 years.

Posterior shoulder instability secondary to reverse humeral avulsion of the glenohumeral ligament.

Background: Posterior shoulder instability resulting from a disruption of the posterior capsular structures has been reported. We present the largest series of these injuries in the published literature, propose a definition and highlight the clinical presentation, radiological findings, and associated injuries.

Materials And Methods: A retrospective review of a single shoulder surgeons database was performed identifying posterior instability cases associated with disruption of the posterior capsule.

Operative outcome of displaced medial-end clavicle fractures in adults.

The results following nonoperative treatment of displaced, medial end clavicle fractures is often unsatisfactory; but no study has yet reported the outcome of operative fixation of these fractures. This study reports the results of open reduction and internal fixation on displaced, medial end clavicle fractures, in five adult patients (aged 25-52 years, mean 43) including 1 patient with a nonunion. The mean follow-up was 3.